A controversial component of Medicare Part D is the coverage gap for prescription expenditures between $2,400 and $5,451. A Kaiser Family Foundation study reported that 15% of Part D enrollees stopped their cardiac medications after reaching the coverage gap, but only about 40% reinitiated medication treatment after drug coverage resumed. Cost-related medication non-adherence can worsen health outcomes, increase rates of hospitalization and overall medical care spending. We believe black/Hispanic Medicare beneficiaries with congestive heart failure (CHF) and/or a recent history of acute myocardial infarction (MI) will likely be affected severely by the coverage gap, but no research has done in this important area. We propose to study whether the coverage gap affects black/Hispanic beneficiaries with CHF/MI more severely than non-Hispanic white beneficiaries, using merged national 2007-2008 Medicare pharmacy and medical claims data. We hypothesize that compared with non-Hispanic whites, after adjusting for socio-demographic and health status, black/Hispanic beneficiaries are more likely to reduce cardiovascular medication use due to the coverage gap and less likely and/or slower to reinitiate medications after discontinuation when drug coverage resumes. Therefore we hypothesize that black/Hispanic patients exposed to the coverage gap will have higher rates of hospitalization and higher non-drug medical costs than do non-Hispanic whites, after adjusting for socio-demographic and health status. Our research team has been at the forefront in Part D related research: our Health Affairs study is one of the first papers to evaluate the effects of the coverage gap on medication use and our NEJM study is the first to demonstrate the offset effects of Part D drug coverage on non-drug medical spending. Little evidence exists on how patients with cardiac diseases respond to the Part D coverage gap, how these responses vary by race/ethnicity. Our study will fill this knowledge gap, by providing critical evidence to policymakers who could potentially redesign Part D benefits or to clinicians who could proactively work with the struggling vulnerable population to improve their health outcomes. PUBLIC HEALTH RELEVANCE: A controversial component of Medicare Part D is the coverage gap for prescription expenditures between $2,400 and $5,451. Black/Hispanic minority beneficiaries with cardiac diseases might be affected most severely by the coverage gap, because almost half of them will reach the coverage gap and will reduce their medication use due to high drug costs. Cost-related medication non-adherence worsens health outcomes, and increased rates of hospitalization and total medical costs. Our proposed study would be the first national study to examine whether the coverage gap affects Black/Hispanic beneficiaries with cardiac diseases more than non-Hispanic white beneficiaries, using merged national 2007-2008 Medicare pharmacy and medical claims data. .